Improvement in the processes of transferring lithographic prints onto glass



UNITED STATES PATENT OFFICE.

OTTO P. \VOLFF, OF CINCINNATI, OHIO, ASSIGNOR TO STROBRIDGE & 00.,

OF SAME PLACE.

IMPROVEMENT IN THE PROCESSES 0F TRANSFERRING LITHOGRAPHIC PRINTS ONTO GLASS, &c.

Specification forming part of Letters Patent No. 145,472, dated December 9, 1873; application filed June 6, 1873.

To all whom it may concern Be it known that I, Orro P. WOLFF, of Cincinnati, county of Hamilton, State of Ohio,

have invented a new and Improved Process of been known; but the process by which this has hitherto been doneknown as the decalcomanic process-is a long and tedious one, besides being uncertain in its results. The method commonly pursued has been, in the first place, to prepare the paper on which the print is to be taken by coating it with a solution of some adhesive gum. This makes it necessary to print from a dry stone, and this can only be done by applying to the moistened stone such a quantity of ink or paint that it will retain suflicient fluidity to produce an impression on the paper after the stone has been dried. This does not give as satisfactory an impression as could be obtained from a moist stone. Again, after the printed surface of the paper has been made to adhere to the glass or other substance, the final process of removing the paper must be conducted with the greatest care, or the picture will be spoiled and all the previous work be lost. Even under the most favorable circumstances, portions of the print are often injured, and have to be touched over by hand, thus causing delay and increased expense.

The object of my invention is, first, to make it possible to print from a wet stone, thus obtaining more perfect and rapid impressions; second, to make it possible to remove the paper, at. the close of the transferring process, with rapidity, and without injury to the print. 1 The various steps of my process are as folows:

First, the paper on which the print is to be taken is coated with'one or two coats of some adhesive gummy solution, as in the ordinary decalcomanie process.

Second, the paper is then coated with a so lution of some transparent resin, as white shellac, dissolved in proof alcohol. This I claim as new and of my invention. The importance of this step in the process will be seen hereafter.

Third, on the paper thus prepared the desired impression is taken from a stone moistened with water and inked with oil-colors, after the ordinary method of taking lithographic prints.

Fourth, for transferring onto glass, the printed surface is then varnished with a per fectly clean, transparent, thin, and quick-dryin g oil-varnish, which must be allowed to dry on until it will not stick to the fingers when applied to it. WVhen the print is to be transferred onto canvas, this varnish is not applied. The print is now ready to be transferred.

Fifth, the glass or canvas (which must be prepared the same as for an ordinary oil-paint- I ing) onto which the print is to be transferred is then varnished with the same varnish which was applied to the print in the fourth stage of the process, (for transferring it onto glass,) but it is not permitted to become quite dry. WVhen it has reached the right state of sticky consistency, to be determined by the judgment of the workman, the face of the print is applied to the varnished glass or canvas, and the two are carefully passed together through a press, in such a way that the air shall be completely excluded from between them.

Sixth, the glass or canvas, with the print adhering to it, is then dipped into water several times, or water is poured over it until the paper can be easily removed. Seventh, when the paper has been removed, the gummy solution, which was applied to it in the first stage of this process, will be exposed at the rear or front surface of the now transferred print, according as the material to which it was transferred was transparent or opaque. If this gummy solution were allowed to remain and harden it would crack, and so mar the print. It must, therefore, be thoroughly washed away with water.

Eighth, when this has been removed, the alcoholic solution of lac or other resin, which was placed on the paper in stage No. 2 of this process, will be exposed, and, being perfectly transparent, beneath it will be seen with perfeet clearness the transferred print. If it was transferred onto glass, the rear or reverse of the picture will be seen through the resinous coating; if to canvas or other opaque material, then the front of the picture will be thus seen.

Ninth, when the transferred picture has become thoroughly dried from the last washing with water, it may be painted or varnished, ((1.) If it was transferred onto glass, its rear sur- "face may be painted of any desired tint, such as will form a suitable ground for the picture when seen through the glass which covers its front surface, (1).) If it was transferred onto canvas or some opaque material, the face of the print should be coated with the same transparent lac solution used in stage No. 2. a

It is then allowed to dry, and the process is completed.

The most important part of my invention, and the one which makes it possible to apply the process, as herein described, with rapidity and success, is the alcoholic solution of lac or other resin, which is applied to the paper to prepare it to receive the impression from the stone. The advantages secured by the use of this solution can be readily pointed out.

First, the paper with which it has been coated can be applied directly to the moistened stone without any danger that the two will adhere together. This obviates the necessity of using more than the ordinary quantity of ink. It also does away with the delay and uncertainty of watching for the moment when the stone is dry enough, and the ink not too dry, to take a good impression.

Second, the different colors can be printed on in rapid succession, without waiting for each to dry before putting the paper on the, stone for the next, as is necessary when the. ston is dry, to prevent adhesion of color to the stone.

Third, toward the close of the process the paper can be removed rapidly, and with no damage to the print, for this solution of la which is impervious to water, lies between the paper and the print, and protects the latter when the paper is taken off.

I firmly believe that by my process, as herein described, lithographs can be transferred onto glass or canvas with far less expenditure of time and labor, and with far greater certainty of success, than by any other process which has hitherto been applied to glass, iron, or any other material. Furthermore, as far as my knowledge extends, the transferring of prints from paper onto canvas has never before been satisfactorily accomplished; yet by my process this can be done with certainty and dispatch, and the result on the canvas presents the appearance of an oil-painting.

I am aware that in transferring prints, 850., a coating of varnish has been used between the gummed surface of the transfer-paper and the print.

What I claim as my invention, and: desire to secure by Letters Patent, is

In the before-described process of preparing and transferring lithographic prints onto glass,

"&c., the employment: of a transparent. solution of white lac, substantially as described, and for the purposes specified.

OTTO P. WOLFF.

Witnesses CHARLES H. SMITH, JEREMIAH F. TWOHIG, 

